Presser-foot mechanism for sewing-machines.



E. ERICKSON.

PRESSER FOOT MECHANISM FOR SEWING MACHINES.

APPLICATION FILED DEC. 4. 1911. RENEWED FEB. 18,1915.

1 1 5 1 ,768. Patented Aug. 31; 1915.

4 SHEETS-SHEET I.

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' COLUMBlA PLANOORAPH co, WASHINGTON, n. c.

E. ERICKSON. PRESSER FOOT MECHANISM FOR SEWING MACHINES. APPLICATION man1150.4.1911. gzmawan FEB. 18,1915.

1.15138 Patented Aug. 31, 1915.

-4 SHEETS-SHEET 2.

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coLummA PLANDGRAPH CD4, WASHINGTON, n. c.

E. ERICKSON.

PRESSER FOOT MECHANISM FOR SEWING MACHINES.

APPLICATION FILED DEC. 4. I91I. RENEWED FEB. I8, I915.

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E. ERICKSON.

PRESSER FOOT MECHANISM FOR SEWING MACHINES.

APPLICATION FILED DEC. 4. I911.

RENEWED FEB. 18,!915.

lmvemiaarz 6 $5 es W TTTED STATES EDWARD ERICKSON,

OF WEST LYNN, MASSACHUSETTS, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS,TO VICTOR SHOE MACHINERY COMPANY, OF BOSTON, MASSA- CHUSETTS, ACORPORATION OF MASSACHUSETTS.

PRESSER-FOOT MECHANISM FOR- SEWING-MACHINES.

Original application filed August 18, 1911, Serial No. 644,769.

Specification of Letters Patent.

4, 1911, Serial No. 663,940. Renewed February 18, 1915. Serial No.9,207.

To all whom it may concern:

Be it known that I, EDWARD ERIGKSON, a citizen of the United States, anda resident of West Lynn in the county of Essex and State ofMassachusetts, have invented certain new and and useful Improvements inPresser-Foot Mechanism for Sewing-Machines of which the following is aspecification.

This invention relates to machines for sewing heavy material such asleather, and refers particularly to the mechanism for controlling thepresser foot of that type known as welt sewing machines.

The object of the invention is to provide an improved mechanism whichwill effect the lockingof the presser foot to hold the work tightlyduring the formation of each stitch, and to release it during the feedof the work.

To this end the present invention consists in the construction andcombination of parts substantially as hereinafter described and claimed.

Of the accompanying drawings,Figure 1 is front elevation of the machinecomplete. Fig. 2 is an el vation from the left of Fig. 1. Fig. 3 is anelevation from the right of Fig. 1. Fig. 4 represents a section on line4-lof Fig. 1, and Fig. represents a detail, partly in section on line5-5 of Fig. e.

In the present application only the presser foot mechanism will bedescribed but for the description and operation of the entire lockstitchsewing machine reference may be made to my application 644;,769, filedAug. 18 1911, of which the present application is a division.

The same reference characters indicate the same or similar parts in allof the views.

In the embodiment of the invention illustrated, the base 30 is formed orprovided with two uprights or standards 31, 32, having bearings for alower main or drive shaft 33 and an upper counter shaft 37 and a fixedshaft 38 on the latter of which are mounted certain parts for operatingthe shuttle 53. The main shaft has a pulley 34: for a power drivingbelt, and has a crank 35 intermediate its ends, to which crank isconnected one end of a pitman 36 for actuating the awl 137 and needle121 said awl and needle in their movements being adapted to pass througha slot 66 in the work support 67 with which a presscr foot 71 coacts.

The work presser comprises an arm 71 having a foot 72 (Figs. 1, 2, 3and 1) to bear on the work supported by arm 67, said arm having a hub 73mounted on a stud 74 supported by standard 32. An arm 75 projectingrearwardly from the hub 7 3 is provided with a toothed segment 76 whichmeshes with a pinion 77 (Fig. 1-) fast on rock shaft 78.

To effect the locking of the presser foot to hold the work tightlyduring the formation of each stitch, and to release it during the feedof the work, the following mecha nism is provided 2-Secured to arm 75 isa segment rack 86, meshing with a pinion 87 having a sleeve hub 88mounted on a crank or wrist pin 89 (see Fig. 5 in connection with 4:) ofa stud rock shaft 90 mounted in standard 32 and carrying an arm 91 atits outer end. The arm 91 has a roll 92 engaging a cam groove 93 in adisk 94 secured to shaft 33,' said cam groove being indicated by dottedlines in Fig. 1. On the wrist pin at the outer end of sleeve hub 88, isa collar 95 havinga ratchet-toothed outer end face 96 engaged by a pin97 projecting from said wrist pin. A spring 98 is coiled around, and hasits ends connected to, the collar and hub so as to constitute a yieldingconnection between said two members and consequently to cause thepresser foot to bear yieldingly on the work with a pressure that may bevaried adjusting the collar rotatively the desired adjustment beingmaintained by the pin 97 engaging one of the end teeth of the collar.Such yielding pressure however ceases when the awl is penetrating tiework. To interrupt this yielding pressure and cause the presser foot toremain immovably in position to resist the force of the upwardly movingawl I provide means for preventing rotation of the pinion 87 at theproper time. Mounted on the hub 88 are two collars 99 and/100, saidcollars inclosing a spring 101 which snugly fits the hub and has its twoends connected to the two collars so that relative rotation of thecollars will tighten the spring on the hub to act as a clutch brake onthe latter, or release it; The collar 99 has an arm 102 provided with aslot which receives a fixed pin 103, whereby said collar is preventedfrom rotating although it presents no obstruction to the lateralmovement of the pinion hub 88 when the wrist pin is shifted. The othercollar 100 has an arm 101 connected by a link 105 with a lever 106fulcrumed on a stud 107 and having a roll 108 engaging a cam groove 109in disk 9 1. This arm 101 is moved downwardly by the cam groove 109 whenit is desired to tighten the brake spring. Pivoted to the lever 106 at110 is an arm 111 having a roll 112 engaging the outer surface of therib which forms the outer wall, of cam groove 109. The other end of thearm.111 is formed or provided with a yoke 113 which embraces aneccentriclla (see dotted lines in Fig. 4) which is mounted on stud107and has an arm 115 which enters a notch 116 in a vertically movable bar117 that is adapted to be lifted manually, as by a suitable treadle, notshown. lVhen-the parts are in the position shown in Fig. 1, the tworolls 108, 112, follow the cam rib and cause the lever 106 to be soactuated-that the collar 100 is rotated sufliciently to tighten thebrake spring 101 and prevent the presser foot from yielding excepting atthe end of the feed movement. The gripping effect of the coiled brakespring 101 is obtained regardless of the thickness of the work. That is,when the presser foot is lifted for the introduction of work and thendescends upon the work under the pressure of spring 98, it may occupy ahigher or a lower position according to the work. But the grip to holdit there will be just as effective whether the work be thick or thin.

The hub 73 of the presser foot arm or leverris provided with an arm 118having a pin 119 which projects across the top of bar 117. lVhen the bar117 is lifted, as when Work is to be introduced, the action on arm, 118is such as to raise the presser foot 72. Before this, however, the arm115 is actuated so as to rock the eccentric 114C and swing arm 111 tothrow the roll 112 out wardly and then as the cam disk 94; rotates, arecess 120 in the inner wall of cam groove 109 comes to a positionopposite roll 108 so as to relieve outward pressure on said roll andthus release the braking effect of spring 101 and permit the presserfoot to be lifted by the further upward movement of bar 117. WVhen thebar 117 is lowered again, a projection 117 (Fig. 4:) therefrom engagesthe studat-the outer end of arm 115 and insures the return of said studinto the notch 116.

Theipresser foot is positively lifted slightly (about. one-sixteenth ofan inch) during eachfeed operation. This is when the roll 92. of.=arms.-.91..is in the position indicatedin jEig. -6. As the sleevehub,,88 is eccentric to the axis of stud 90 which carries arm 91,movement of arm 91 toward said position swings said hub 88 laterally. Atthis time, the brake spring 101 is holding pinion 87 locked so that thesaid lateral movement of the pinion 87 acts through the rack 86 tooscillate the arm 75 and raise the foot 72 slightly but positively, sothat the work can be fed freely by the awl.

A spring 101 is coiled upon the hub 88 of pinion 87 in such directionthat, as it is tightened to apply a braking action, it tightens in suchdirection as to add its force to that of spring 98, which latter springcauses the presser foot to bear yieldingly upon the work. Thisadditional force applied to the presser foot by the tightening of thespring 101 is due to the increased frictional contact of said springwith the periphery of the hub 88 which tends to rotate said hub in thedirection that the spring 101 is being wound, this directioncorresponding to the direction that the tension of the spring98 acts.This additional pressure continues to be increased until the arm 10-1comes to a rest at the end of its downward movement. The momentaryaddition of the force of spring 101 to that of spring 98 causes thepresser foot to hear more heavily upon the work just before the lock ingoccurs due to the complete binding of the brake spring 101 upon saidhub. This action, however, does not interfere with the lifting of thepresser foot to permit the awl to feed when the crankmounted stud 89 ismoved by the actuation of the arm 91. The arm 91 is actuated at theproper time to cause the stud 89 to shift about the aXis of the studshaft to which said arm 91 is connected, to cause the presser foot to belifted to permit the awl to feed the work. This provision enables thework to be properly fed by the awl, even when the stock is soft.Consequently, the work when being fed does not have to be pulled alongby the awl against the resistance of any spring pressure whateverapplied to the presser foot.

I claim:

1. Presser foot mechanism'for sewing machines comprising in combinationa lever having a presser foot and a segment rack, a pinion meshing withsaid rack, means for yieldingly actuating the pinion to cause the footof said lever to bear yieldingly on the work after the completion of thefeed, means for holding the lever rigidly during other operations, meansfor positively lifting the presserfoot during each feed operation, ,amanually operable presser-foot lifter, and connections for releasing thelever holding means when said manually operablelifter is actuated.

Presser foot mechanism for sewing machines comprisingin combination alever having a presser foot and a segment rack, a pinion meshing withsaid rack, means for yieldingly actuating the pinion to cause the footof said lever to bear yieldingly on the work after the completion of thefeed, a brake device to hold the lever rigidly at predetermined times,means for positively lifting the presser foot during each feedoperation, means for bringing said brake device into operation when theawl is penetrating the work, a manually operable presser-foot lifter,and connections for releasing the brake when said manually operablelifter is actuated.

3. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foot, a toothed segment carried by said lever,a pinion in permanent engagement with said segment and provided with alateral hub, a spring for yieldingly opposing rotation of said pinion inone direction, a brake spring coiled on the hub of said pinion, andmeans for intermittently tightening said brake spring, consisting inpart of two collars loosely mounted on said hub and to each of which anend of said spring is connected.

4:. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foot, a toothed segment carried by said lever,a stud having a sleeve mounted on it, said sleeve having a pinion inpermanent engagement with said segment, a collar adjustably mounted onsaid stud, a brake spring coiled on the hub of said pinion, and meansfor intermittently tightening said brake spring.

5. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foot, a toothed segment carried by said lever,a stud shaft having a crank pin, a sleeve mounted on said crank pin andhaving a pinion engaging said segment, a spring for yieldingly opposingrotation of the sleeve and pinion, an arm con- &

nected to said stud shaft, and means for oscillating said arm and studshaft.

6. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foot, a toothed segment carried by said lever,a crank-mounted stud having a sleeve mounted on it, said sleeve having apinion engaging said segment, brake mechanism for positively preventingrotation of the sleeve in either direction at predetermined times, andmeans for intermittently changing the position of the crank-mountedstud.

7. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foo-t, a toothed segment carried by said lever,a stud having asleeve mounted on it, said sleeve having a pinionengaging said segment, two collars mounted on said sleeve, a springsurrounding the sleeve and having its ends connected to the two collars,and means for actuating one of said collars to tighten the spring on thesleeve and prevent its rotation at predetermined times.

8. Presser foot mechanism for sewing machines comprising in combinationa lever having a presser foot, a toothed segment carried by said lever,a crank-mounted stud having a sleeve mounted on it, said sleeve having apinion engaging said segment,

brake mechanism for positively preventing rotation of the sleeve ineither direction at predetermined times, means for intermittentlychanging the position of the crankmounted stud, and means for manuallyrelfeasing the brake and lifting the presser oot.

In testimony whereof I have afiixed my signature, in presence of twowitnesses.

EDWVARD ERICKSON.

Witnesses:

A. W. HARRISON, J. M. MURPHY.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, I). G.

